The primary goal of this study is the exploitation of the guinea pig inclusion conjunctivitis animal model for studies refereable to human chlamydial infections. Thus, attempts will be made to determine the pathogenic events involved in the transmission of chlamydiae from the eye to the lung and gastrointestinal tract and to assess the clinical and pathologic significance of chlamydial infection in these sites and in the female reproductive tract. In addition, efforts will be made to study the mechanism of resistance or immunity to infection with Chlamydia trachomatis resulting from previous exposure and to determine the relationship between specific antibody classes or cell types on the outcome of infection.